WEBVTT
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So my name is David Britt. I'm a
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professor of chemistry at the University of
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California campus in Davis, California.
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So, I'm interested in
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how photosynthesis works and
from a point of view of a fuels and the
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environment.
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All of our fossil fuels really started
with photosynthesis, so over millions and
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millions of years,
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carbon dioxide's taken out of the
atmosphere and turned in the things like
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sugars with light energy; water has
been converted to oxygen, so the oxygen
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in our atmosphere comes from
photosynthesis and fossil fuels comes
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from the product of those reactions,
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you know, buried in the earth and turned
into things like petroleum over long
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periods of time. So there's a lot of
interest in the biochemistry
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community in can we harness
photosynthesis to make fuels directly?
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So, for example, one thing we might do
that we're trying to work on is using
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light and photosynthesis to split water: H2O - make O2 -
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and then the H's are combined to make
hydrogen gas, which can be used as a fuel
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for example in fuel cell automobiles
that are coming online now. So that would
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be a very efficient thing because you
take water turn it into a fuel and then
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perhaps use the fuel to just generate
water again, so you've got a nice benign
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energy cycle that doesn't involve carbon
- CO2 at all.
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So that's one of our goals.
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So my own background
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is I entered college studying
physics but I was very interested in
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physics not for pure physics sake but
learning about what you could learn
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about the universe -
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astrophysics, geophysics, biophysics.
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So I went to grad school at the University
of California, Berkeley. I got interested
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in photosynthesis because, as a physicist,
light interacting with matter is physics
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but this is now area that took me into
biochemistry because we're looking at
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how enzymes function to, for example,
split water and make hydrogen, like I'm
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saying.
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So, as a graduate student, I started being
trained in pure physics but transitioned
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into the more biochemical work because I
was intellectually interested in the
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fascinating
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biochemistry of photosynthesis.
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So, one of the things we want to do,
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as a society, is reduce our reliance on
fossil fuels and, as I think everyone
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knows now, the problem with fossil - one
problem of the fossil fuels is you're
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releasing CO2 when you burn them.
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So renewable energy is very important and it can be done in a biological fashion,
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for example, splitting water with
photosystem 2 and making hydrogen with
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hydrogenase, but there are many other
possibilities for how you can use
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enzymes to make liquid fuels, etc. So
if you make a liquid fuel using
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CO2 from the atmosphere even then when you burn it
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CO2 comes out when you burn it but
you're just replacing what you have taken
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out, so its carbon neutral -
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you're not adding to the carbon, like
when you burn a petroleum, for example.
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As the planet increases its energy
consumption, we certainly need to look at
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more renewable fuels. The other thing I
would add is if you learn how these
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enzymes work, you can actually learn
fundamental chemistry from biochemistry
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that you could apply, for example, to
artificial systems where you take the
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lessons from biochemistry at all the
hard-working biochemist develop in their
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research and apply it to, for example,
things where you might use photovoltaics
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to harvest light but you do the
catalysis with synthetic catalysts that
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have been designed on the principles
that we've learned from biochemistry.
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So, biochemistry can inform artificial
synthetic chemistry as well, allowing you
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to work with hard materials like
photovoltaic cells, instead of just
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working with biological enzymes.